1. Field of the Invention
The present invention relates to an inkjet recording device provided with a line engine.
2. Description of the Related Art
As an inkjet recording device/image forming apparatus for performing recording by jetting ink droplets from a recording head, there is a line ink jet type provided with a line engine in which plural recording heads (hereinafter, also simply referred to as “heads”) are aligned in a main scanning direction. As such a line engine configuration, there is known a configuration where one recording head is replaceable.
However, in a conventional inkjet recording device in which one head is replaceable in the line engine, when an arbitrary head fails or breaks, only the corresponding head needs to be replaced.
An ink supply flow path in a line engine configuration frequently includes a manifold for distributing ink to the respective heads from the sub tank. With such a configuration of the supply flow path, in order to enable the replacement of one head, the size of the device is increased, the operation of replacing a head is inefficient, and the cost of the device is increased.
Furthermore, in the conventional line engine configuration, when filling ink into a head after replacement, air bubbles are discharged not only from the replaced head; ink is discharged together with air bubbles substantially equal from other heads as well. Thus, in such a configuration, by filling ink in the head after replacement, a large amount of ink is discarded, and the operation of filling the ink in the head takes a long time.
Patent Document 1 discloses a simple configuration for discharging air bubbles stuck in a distributor, and reducing the amount of ink that becomes waste liquid flowing out together when the air bubbles are discharged. This configuration includes a distributor for distributing and supplying ink to the respective heads; an electromagnetic valve, provided in the distributor, for opening and closing an air bubble discharge opening; and a pump provided between the sub tank and the distributor. In this configuration, ink is sent to the distributor so that the air bubbles in the distributor are discharged from the air bubble discharge opening.
Furthermore, Patent Document 2 discloses a configuration for reducing the size of the head tank (referred to as “sub tank” in Patent Document 2) and increasing the discharged air bubbles in the head tank. This configuration includes a filter member provided in the head tank, which divides the head tank into an upstream chamber and a downstream chamber; a supply path configured to supply the ink from the downstream chamber of the ink storing unit to the head; and a discharge path configured to discharge the ink discharged from a discharge opening of the head to the outside.
However, both of these devices have complex configurations, and problems remain unsolved as to the size of the device is increased, the operation of in replacing a head is inefficient, and the cost of the device is increased.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-131959    Patent Document 2: Japanese Laid-Open Patent Publication No. 2011-148101